GLASTONBURY — Donevin O'Reilly is the "Dog" of the Glastonbury football team.

Don't be alarmed. "Dog" is complimentary term.

"Dog guards the slot receiver," Glastonbury coach Scott Daniels said. "He has to be quick enough to cover passes and physical enough to come up and stop the run."

O'Reilly has contributed on both sides of the ball for Glastonbury, which is 8-3 and the No. 4 seed in the Class LL large school category. The Tomahawks will need all of what he offers when they go against No. 1 Southington (10-0) Saturday at 2 p.m. in a semifinal game. Southington has been No. 1 in the Courant's football ratings all season.

As a running back, O'Reilly leads the Tomahawks in rushing yards (1,209) and touchdowns (11).

"He gives us that threat in a lot of spots," Daniels said. "He's a hard runner. There aren't many who can run downhill and outside and still be as effective. And once he gets in the open field, he's shifty. We can swing screen passes to him, put him in the slot, or run him off tackle."

Video: Glastonbury's Donevin O'Reilly

Glastonbury running back/defensive back Donevin O'Reilly on his versatility on the football field.

Glastonbury running back/defensive back Donevin O'Reilly on his versatility on the football field.

O'Reilly, a 5-foot-9, 180-pound senior, said he often deceives opponents with his inside running ability.

"After games, coaches have told me, 'The way we look at you doesn't really reflect the way you run.' "

O'Reilly's top rushing games this season were 217 yards against Manchester, 144 against Norwich Free Academy and 138 against Conard-West Hartford. He had TD runs of 40 and 52 yards in the Manchester game.

He has 2,002 yards in his career for an average of 6.7 yards a carry. On defense he has 137 tackles overall, including 48 this year.

O'Reilly said his football idol is his brother Devin, who is three years older. Devin, who played at Glastonbury (2009-11), had 42 receptions for 543 yards and eight TDs, ran for 224 yards and seven TDs and made 127 overall tackles.

"Devin is at Merrimack," O'Reilly said. "No one works harder in workouts than him. If he didn't make a weight, he'd take a rest, come back and get it. He got through the pain.

"I've taken that and used it here. No matter how tough it is, I'll be tougher."

O'Reilly is so tough and versatile that he also can return punts and kickoffs and be on kickoff coverage teams. Daniels has to make a point to try to get him out of games.

"He'd play every play if I let him, so I try to get him out for a play or two when I can," Daniels said.

O'Reilly downplayed his endurance. "I don't think about it," he said. "I'm just playing football."

Glastonbury has had an up-and-down season. It started with a 41-38 loss at Southington and a 20-14 overtime loss to Hall-West Hartford. Then Glastonbury won eight of its past nine games.

"After those first two losses we beat South Windsor [42-0]," O'Reilly said. "Our next game was at NFA, a good team that's now in the playoffs [LL-Large]. We won 24-0. That was our turning point; it was time to step up and to show our ability and toughness or to retreat and not be the team we could be."

O'Reilly has played every game, despite nursing some injuries. None was enough to put him on the sidelines, though.

He and his teammates are proud to be part of the seventh consecutive Glastonbury team to play in the LL postseason.

"My personal highlight so far this year was — even though we lost — at Southington in the opener," he said. "The atmosphere was electric. They have quality players and a team that I respect. It was pure, competitive football."

The atmosphere should be even more charged Saturday.

"Quick, fast and hard-hitting is the kind of game we expect," O'Reilly said. "I know in this game, like every game I've ever played, is to leave everything out there, no regrets; just playing football."